Transmissions having electronic controls for ratio interchange generally have a backup system which will permit continued operation of the vehicle in the event of an electrical stoppage. These controls generally condition the transmission for a forward ratio, such as third, in a five-speed transmission and no other forward operation ratios.
Some controls will permit the manual selection of one forward and one reverse ratio, such that the vehicle can continue to be driven to a place of repair. Other controls will condition the transmission to a high gear ratio if the electrical stoppage occurs at high vehicle speeds to maintain this high gear ratio until the vehicle brought to a halt. After stopping, the vehicle transmission is generally then operable in a single forward ratio or reverse ratio until the electrical stoppage is overcome.